In spite of the challenges and uncertainties that the larger scientific community is currently facing, I am delighted and humbled to accept one of the British Ecological Society’s Ecologist in Africa research grant for 2020. The grant will support my historical ecology project whose main goal is to apply palaeoecological and archaeological proxies to investigate the extent of anthropogenic impacts on vegetation structure and composition of one of the Kenyan Central highlands before, during, and after the colonial period.
The Aberdare range forest provide an ideal setting for this study because they have been farmed by local populations since long before colonialism, and they were heavily impacted during colonial times because of their fertile soils. This pilot project aims to reveal the land-use and land-cover dynamics of the Aberdare range forest, and it is hoped that eventually similar studies will be undertaken in other parts of the Kenyan highland forests.
Gosling, W.D., Sear, D.A., Hassall, J.D., Langdon, P.G., Bönnen, M.N.T., Driessen, T.D., van Kemenade, Z.R., Noort, K., Leng, M.J., Croudace, I.W., Bourne, A.J. & McMichael, C.N.H. (2020) Human occupation and ecosystem change on Upolu (Samoa) during the Holocene. Journal of Biogeography DOI: 10.1111/jbi.13783
Note: Co-authors Bönnen, Driessen, van Kemenade, and Noort all contributed to this work as part of the research projects related to their MSc or BSc degrees within the Department of Ecosystem & Landscape Dynamics at the University of Amsterdam.
The paper we discussed was “Columbus’ footprint in Hispaniola: A paleoenvironmental record of indigenous and colonial impacts on the landscape of the central Cibao Valley, northern Dominican Republic” by Castilla-Beltrán et al (2018). The paper provides a multi-proxy paleoecological reconstruction of the Caribbean island nation of the Dominican Republic, spanning the last 1100 years. Personally I found this to be a very interesting paper, packed with information and interpretations on the impact of anthropogenic factors on past Caribbean environments. What this paper nicely demonstrates is the difference in impact between pre-colonial and post-colonial societies on the vegetation of the Dominican republic. Pre-colonial Hispaniola was inhabited by indigenous societies, the Taíno people, and while this paper clearly shows them having had an environmental impact in the form of fire management (e.g. for slash and burn agriculture), small scale deforestation and the introduction of cultivars such as maize and squash, their environmental impact remains modest compared to post-colonial disturbances. Columbus arriving in AD 1492 signified a moment of change in the landscape. The paleorecord suggests that, after an initial collapse of the Taíno population, the colonization of the Dominican Republic by the Spanish brought with it deforestation, crop monoculture and the introduction of European livestock, all of which still characterizes the landscape to this day.
The discussion mainly focused on the chronology used. One of the radiocarbon samples was excluded from the age-depth model for no apparent reason, which led us to discuss the importance of critically evaluating your calibrated radiocarbon dates and which ones to incorporate in your age-depth model. The age-depth model currently used implied a shift in pollen composition c. 30 years before the arrival of the Spanish. We were unsure how to interpret these findings because you would expect the shift to happen afterwards, so my initial thought was that it had to be a fault in the chronology. This chronology however does imply a large charcoal peak followed by a rapid decline that coincides precisely with the arrival of the Spanish, and it turned out that this was the reason the authors settled on this chronology.
Even though this paper by Castilla-Beltrán et al. didn’t spark any heated discussions, its incorporation of ecology, botany, history, archeology and geology still showcases the interdisciplinary nature of paleoecology, something I very much enjoy about this field of research.
Over the last two weeks I have been giving my lectures at the VU Amsterdam “Scientific Methods in Archaeology” bachelor program. In my lectures we think about how to detect past environmental change with particular reference to tracking past human activities. As part of our exploration of past human-environment-climate interactions each student is asked to choose a scientific article, summerise it, and we then discuss it in class. The three papers sected this year covered the Neolithic of the Netherlands (Weijdema et al., 2011), a overview of Mediterranean and north African cultural adaptations to drough events during the Holocene (Mercuri et al., 2011), and an exploration of the role of humans in mega-faunal extinctions in South America (Villavicencio et al., 2015). All papers provided interesting points of discussion and an opportunity to think about different aspects of how we investigate past environmental and societal change.
The 2018 edition of the University of Amsterdam masters course “Environments Through Time” is now up and running. The course sits at the interface between ecology, physical geography and archaeology and seeks to provide students with a better understanding of how long-term (>100’s years) datasets can provide insights in to past environmental change.
In the first week of the course the students had to present their ‘favourite’ paper in just three (3) minutes! Quite a challenge and lots of fun. This years selection of papers themed around:
mega-fauna extinctions (Bakker et al., 2016; Gill et al., 2009; van der Kaars et al., 2017),
impacts of human land use practices (Bitusik et al., 2018; Carson et al., 2014; Chepstow-Lusty et al., 2009; Gauthier et al., 2010; Tisdall et al., 2018), and
climatic drivers of vegetation change (Haug et al., 2001; Tierney et al., 2017; Tudhope et al., 2001).
For full list of papers presented see below.
In the second and third weeks (now ongoing) students get to deconstruct published chronologies and conduct time series analsis of multi-proxy datasets. Data for these excercises is frequently is extracted from databases such as Neotoma, Pangea, NOAA – paleoclimatology datasets database and the Global Charcoal Database – which shows the importance of these open access databases for developing effective research led eductation, as well as pushing forward to frontiers of research.
Hooghiemstra, H., Olijhoek, T., Hoogland, M., Prins, M., van Geel, B., Donders, T., Gosling, W.D. & Hofman, C. (2018) Columbus’ environmental impact in the New World: Land use change in the Yaque River valley, Dominican Republic. The Holocene. Online DOI: 10.1177/0959683618788732
Abstract submission is now open for INQUA 2019 in Dublin Ireland (25-31 July 2019). Please consider submitting to the special session I am co-organizing on landscape change in the tropics. Submissions welcome from the fields of biogeography, palaeoecology, geomorphology, volcanology, and archaeology. Click here to submit your abstract.TITLE: The changing tropical landscape
ORGANIZERS: William D. Gosling and Crystal N.H. McMichael (University of Amsterdam)
Eighteenth century explorers marveled at the diversity of tropical ecosystems seemingly untouched by human activity. As a result of these observations, the notion of tropical stability, in terms of vegetation and climate, came to underpin theories of evolution, ecology, and biogeography. Gradually, however, it has become apparent that tropical landscapes have changed markedly through time in response to global climate cycles, (a)biotic factors, and human activity. For example, Continue Reading
Yesterday (day 3) was excursion day of the AFQUA conference (photos to follow). Day 4 of the meeting was back in the National Museum Nairobi and kicked off with a session on “African archaeological landscapes”. The opening talk reviewed the career of Karl Butzer who coined the term ‘geoarchaeology’ back in the 1970’s when writing about his work integrating geological, archaeological and anthropological information (C.A. Cordova). Two talks then followed highlighting work on Lake Makagadikgadi from the perspective of archaeology and landscapes (D.S.G Thomas) and geochemical fingerprinting of stone tools to determine their source (D.J. Nash).
To take us up to lunch Boris Vanniere and Daniele Colombaroli gave a ‘double header’ plenary talk highlighting the exciting advances in the development of the Global Charcoal Database and how understanding past fire histories in Africa is key to interpreting environmental change. The after lunch session continued the palaeo-fire theme with records from Lake Botswana (C.E. Cordova), Lake Bosumtwi (W.D. Gosling – me), and Madagascar presented (A. Razafimanantsoa); as well as work on the usefulness of the morphometric’s of charcoal in determining the plant of origin (L.Bremond).
In the final session of the day we were back to “Southern Africa” as a theme. Under which banner we were “boggled” by sea-surface and sub-surface temperature reconstructions (M.A. Berke), shown how to extract climate records from Hyrax middens (B.M. Chase) and given insights into the past flora of the Cape Floristic region from fossil pollen records spanning 130,000 years (L.J. Quick).
Castilla-Beltrán, A., Hooghiemstra, H., Hoogland, M.L.P., Pagán-Jiménez, J., van Geel, B., Field, M.H., Prins, M., Donders, T., Malatesta, E.H., Hung, J.U., McMichael, C.H., Gosling, W.D. & Hofman, C.L. Columbus’ footprint in Hispaniola: a paleoenvironmental record of Indigenous and Colonial impacts on the landscape of the central Cibao Valley, northern Dominican Republic. Anthropocene. DOI: 10.1016/j.ancene.2018.05.003
Since being appointed as an Associate Editor of Vegetation History & Archaeobotany last year I have the pleasure of working on a number of exciting and interesting manuscripts from the tropics. I am particularly delighted that the first of these (Astudillo, 2018) has now been published. I particularly liked this manuscript because of: (i) the close relationship that was shown between the historical and fossil records, and (ii) the clear signal shown from working on a island system. This linkage is something I have been thinking about in my own research on Mauritius recently (Gosling et al., 2017) and is, I believe, particularly valuable to do because it demonstrates the validity of techniques to track human activity when applied in contexts without historical documentation. The impact of people on the Galapagos is shown by Astudillo (2018) from investigation of multiple proxies (charcoal, phytoliths and macrofossils) to build up a comprehensive picture of human impacts on one of the most famous places for biodiversity on Earth. Hopefully this study is just the start of investigations into past human impacts on the Galapagos islands, and I hope that you enjoy reading the manuscript!